1. Field of the Invention:
This invention is related to packaging semi-conductor chips and more particularly, but not by way of limitation, to collet holders used to hold die during brazing operation for insertion of the die into its package.
2. Description of the Prior Art:
The semi-conductor devices are brazed into their carriers and subsequently connected to the carrier leads. The collet holder provides a means of mechanically holding the collet, a means of applying a vacuum through the collet in order to hold the die in position for the brazing operation and it also provides a course of heat to the collet which is required to assist in melting the brazing alloy. The collet is made of a carbide which is a very poor conductor of heat which has forced users to add a resistance heater around the shank of the collet in order to obtain a proper brazing temperature.
Additionally, the atmosphere must not be contaminated and oxidation must be prohibited. This is typically accomplished by flooding the area with nitrogen gas, but unless the gas is preheated to brazing temperatures and unless it is applied uniformly to the area of interest in such a way as to exclude atmospheric contamination, it may interfere with the proper completion of the brazing operation.